Re: what next ...please HELP
1st - Tighten every bolt on that engine as they're no doubt loose if it ran that hot. The head bolts must be torqued properly in a specific sequence. Seer you service manual.
2nd - With the engine not running but with the key in the on position, find the TAN (overheat sensor) wire protruding from the cylinder head and grouns it to the block. The warning horn or most likely in your case the overheat light should come on. If it does not, find out why as that's the only warning you'll receive when the engine starts to overheat.